The present invention relates to a method of automatically correcting magnification and non-linearity of scanning electron microscope.
When a magnification and/or non-linearity of scanning electron microscope deviates from nominal values, it is necessary to perform the correction of these parameters with a desired precisions.
No known methods are known for performing automatic correction of the magnification and/or non linearity. It is believed that it is exceptionally important to perform the automatic correction of these parameters.
Accordingly, it is an object of present invention to provide an automatic correction of magnification and/or non-linearity of an electronic microscope to achieve the nominal values of these parameters.
In keeping with these objects and with others which will become apparent hereinafter, one feature of present invention, resides, briefly stated, in a method of a method of automatically correcting magnification and non-linearity of scanning electron microscope, in which the following steps are performed:
A method of automatically correcting magnification and/or non linearity of scanning electron microscope has the steps of loading a reference material in the microscope, inputting a pitch of the reference material and a nominal magnification of the microscope, obtaining an image of the reference material, determining a pitch and/or a linearity of the image of the reference material, comparing the pitch of the image with the inputted pitch of the reference material to obtain a ratio indicative of the magnification and/or comparing the magnification in different locations across an image field indicative of the linearity, comparing the thusly determined magnification with the nominal magnification, and if an error of magnification exceeds a predetermined value, adjusting the scanning electron microscope.
The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.